#3057. Update tests to follow assertion text

Author: sgrekhov

TypeSystem/flow-analysis/reachability_A08_t01.dart

@@ -37,8 +37,9 @@
 
 main() {
   int i;
-  Null n = null;
-  if (n == null) {
+  Null n1 = null;
+  Null n2 = null;
+  if (n1 == n2) {
     i = 42; // condition is always true therefore `i` must be definitely assigned
   }
   i; // It's not an error to read local non-nullable variable if it is definitely assigned

TypeSystem/flow-analysis/reachability_A08_t02.dart

@@ -35,11 +35,12 @@
 
 // Requirements=nnbd-strong
 
-Null get n => null;
+Null get n1 => null;
 
 main() {
   int i;
-  if (n == null) {
+  Null n2;
+  if (n1 == n2) {
     i = 42; // condition is always true therefore `i` must be definitely assigned
   }
   i; // It's not an error to read local non-nullable variable if it is definitely assigned

TypeSystem/flow-analysis/reachability_A08_t03.dart

@@ -27,8 +27,8 @@
 /// `(int? x) => x == (x = null) ? true : x.isEven`, which tries to call
 /// `null.isEven` in the event of a non-null input).
 ///
-/// @description Checks reachability after variable or getter. Test non-nullable
-/// type.
+/// @description Checks that if `equivalentToNull(T2)` and `T1` is non-nullable,
+/// then `true(N) = unreachable(after(E2))` and `false(N) = after(E2)`.
 /// @author [email protected]
 /// @issue 41981
 /// @issue 60114

TypeSystem/flow-analysis/reachability_A08_t04.dart

@@ -27,8 +27,8 @@
 /// `(int? x) => x == (x = null) ? true : x.isEven`, which tries to call
 /// `null.isEven` in the event of a non-null input).
 ///
-/// @description Checks reachability after variable or getter. Test getter of
-/// non-nullable type
+/// @description Checks that if `equivalentToNull(T1)` and `T2` is non-nullable,
+/// then `true(N) = unreachable(after(E2))` and `false(N) = after(E2)`.
 /// @author [email protected]
 /// @issue 41981
 /// @issue 60114
@@ -39,7 +39,7 @@ String get s => "Lily was here";
 
 main() {
   late int i;
-  if (s == null) {  // ignore: unnecessary_null_comparison
+  if (null == s) {  // ignore: unnecessary_null_comparison
     i = 42; // `i` is definitely unassigned
   }
   i;

TypeSystem/flow-analysis/reachability_A09_t01.dart

@@ -6,14 +6,16 @@
 /// treated as equivalent to the expression `!(E1 == E2)`.
 ///
 /// @description Checks that an expression of the form `E1 != E2` is treated as
-/// equivalent to the expression `!(E1 == E2)`.
+/// equivalent to the expression `!(E1 == E2)`. Test `equivalentToNull(T1)` and
+/// `equivalentToNull(T2) case.
 /// @author [email protected]
 /// @issue 41981
 
 main() {
   late int i;
-  Null n = null;
-  if (n != null) {
+  Null n1 = null;
+  Null n2 = null;
+  if (n1 != n2) {
     i = 42; // Variable is initialized in a dead code. This leaves it definitely unassigned
   }
   i;  // It is an error to read a local late variable when it is definitely unassigned.

TypeSystem/flow-analysis/reachability_A09_t02.dart

@@ -6,15 +6,17 @@
 /// treated as equivalent to the expression `!(E1 == E2)`.
 ///
 /// @description Checks that an expression of the form `E1 != E2` is treated as
-/// equivalent to the expression `!(E1 == E2)`. Test getter of the type `Null`.
+/// equivalent to the expression `!(E1 == E2)`. Test `equivalentToNull(T1)` and
+/// `equivalentToNull(T2) case and getter of the type `Null`.
 /// @author [email protected]
 /// @issue 41981
 
-Null get n => null;
+Null get n1 => null;
 
 main() {
   late int i;
-  if (n != null) {
+  Null n2;
+  if (n1 != n2) {
     i = 42; // Variable is initialized in a dead code. This leaves it definitely unassigned
   }
   i; // It is an error to read a local late variable when it is definitely unassigned.

TypeSystem/flow-analysis/reachability_A09_t03.dart

@@ -6,7 +6,8 @@
 /// treated as equivalent to the expression `!(E1 == E2)`.
 ///
 /// @description Checks that an expression of the form `E1 != E2` is treated as
-/// equivalent to the expression `!(E1 == E2)`. Test a non-nullable type
+/// equivalent to the expression `!(E1 == E2)`. Test `equivalentToNull(T2)` and
+/// `T1` is non-nullable case.
 /// @author [email protected]
 /// @issue 41985
 /// @issue 60114

TypeSystem/flow-analysis/reachability_A09_t04.dart

@@ -15,8 +15,8 @@
 ///  Let null(N) = unreachable(before(N)).
 ///  Let notNull(N) = before(N).
 ///
-/// @description Checks reachability after variable or getter. Test getter of
-/// non-nullable type
+/// @description Checks reachability after variable or getter. Test
+/// `equivalentToNull(T1)` and `T2` is non-nullable
 /// @author [email protected]
 /// @issue 41985
 /// @issue 60114
@@ -25,7 +25,7 @@ String get s => "Lily was here";
 
 main() {
   int i;
-  if (s != null) { // ignore: unnecessary_null_comparison
+  if (null != s) { // ignore: unnecessary_null_comparison
     i = 42; // `i` is definitely assigned here
   }
   i; // It is not an error to read a local non-nullable variable which is definitely assigned